Oxford - Leamington - Coventry - Nuneaton is being wired as part of the electric spine but there are still the capacity constraints in crossing Coventry on the level. But with the new north chord at Nuneaton (does much traffic use this yet?) you'd then have an alternative electrified route from the WCML to Southampton (via Bedford), if Nuneaton to Wigston were to be wired also that is.
Also I'd have thought there should be some capacity between Birmingham and Nuneaton now that Daw Mill has closed.
Our HH traffic from Bardon Hill to Crewe often uses the new chord at Nuneaton, it saves no end of time / messing about trying to get across the WCML... 30mph off the Leicester line then 50 down onto the WCML where it trails into the Down Slow